Piston-ring



E. R. NORMAN.

PISTON RING.

APPLICATION FILED JULY 9.1917.

1,367,710. I Patented Feb. 8,1921;

I S R? w. 0 2 W a. V n 7 EDWARD R. NGRMAN, F UHICAGQ, ILLINOIS.

PIfiTGN-RING.

11,366? it 11th,

%lhis invention relates to one-piece expansive p1ston rings, which may be used no various organizations, as for example on pistons of diiferent kinds of engines.

The primary object of my invent on 1s to provide a one-piece self-expansive ringhaving certain features whereby the inner tongues of the joint are radlally thicker than their associated outer shoulders to give greater strength and durability to the joint,

and the joint ends are made up of curves so they do not have any square shoulders that weaken the ring and the liab lity of the tongues being broken in springing the ring into position is eliminated. Other objects will be apparent from the disclosure.

My expansive one-piece pistonring and the process of inalning the same are illustrated in the accompanying drawings wherein-==- Figure 1 shows a side view of the original blank from which the ring is made; I

ll ig. a is a View showing the operation of milling one side of the joint as by a top cutter or milling tool;

Fig. 3 is milling the other side by a lower cutter or miller, and showing parts tor the joint as completed by the operation oi the cutters;

t is a detail side view of the ends when the joint closed; I n

Fig, 5 tea detail plan View at the end with the ring in closed position;

Fig. 6 is a detail plan view of the after the parts of the joint are cut;

Fig. '3 is a side view of the ends of the ring in distorted position showing the first step in the fatiguing process;

blank liig. 23 a side riew oi the ends at the ring at 'diherent positions during the fatiguing process, and

lhig. 9 is a diagrammatic view. lln forming my self-expanding one-piece ring by my process ll produce by car Specification of Letters Patent. a earances. July a, 1917. Serial no.

i ing orotherwise a ring a View showing the operation of Patented Feb. h, 1921..

manor; 7

shaped blank B of suitable material, such as gray 11011. The

shape of this blank is slightly eccentric; the

rightrhand-halt of the blank is made on a radius struck from the position so, and the left-hand half is made on a radius struck from the position 3 the center of the blank being at e; by this arrangement one (here the vertical) diameter of the blank is shorter than that at a right angle (here the horizontal' diameter), and the joint is out at either end of this shorter diameter of the blank or casting as at b, all as shown in Fig. 1. The blank in its size exceeds that of the finished ring in closed position by an amount equal to the amount of material removed at the joint to properly make the joint plus shrinkage and the amount allowed to properly finish the periphery, of the ring. The width of the blank should exceed that of the finished ring by allowing for shrinkage and machining or grinding. The joint is cut on the shorter diameter of the blank as shown.

in Fig. 1, with a suitable cutter or milling tool. In cutting the goint the inner tongues ness of the tongues may be anything greater than that of the shoulders but in practice ll refer to maize them on the ratio of 3 to 2. hreiferably the blank is placed in a fined position, and a revolving upper cutter moves from position A toward the center of the blanlr at a suitable point at one side of the dividing line 5 to position at A?" in Fig. 2, cutting a round notch N in the outer taco oi the blanlr to a width equal to one-halt oi the width of its outer face or periphew and to a depth equal to twai'iiths of its radial thicln nose; the cutter then moves laterally to position A cutting a curved recess it on the same radius as-the ring at the ioint and forming a tongue il which is three-fifths oi? theradial thickness oi the blanln and then moves from A to laterally and inwardly cutting a round end or ti on the tongtn's and then moves from A aterally through till curved recess R on thesanie radius as the ringat the joint and forming a shoulder S which is two-fifths oi the radial thickness of the blank and having a round notch i l.

This completes its operation and the cutter then moves to A. The blank is then syrunietrically milled or cut away on the opposite side of the dividing line, the operation being similar to the first. The operations may be either simultaneous or separate as desired. in the present instance l employ a lower cutter which moves trons positionld toward the center of the lolanr to position B cutting a round notch N in the outer i5 face of the ring to a Width equal to onedcalt oi the width of its outer face and to a depth equal to two-fifths oi its radial thickness; the cutter then moves laterally to B cutting a curved recess on the same radius as the as ring at the joint and forming a tongue T which is three-lilths of the radial thickness of the blanlr, and then moves from B to T5 laterally and inwardly cutting a rounding end. or tip on the latter tongue, then from B through E to P1 leaving a cheek, and from B to B cutting laterally and inwardly to term a rounded end or tip and from B to B cutting a curved recess on the radius of the ring at the joint and forming so a shoulder S, which is two-fifths of the radial thickness of the blank and having a round notch N This completes the operation and also results in severing the blank at the line 6.

The tongues are on the inner side of the ring. the shoulders being on the outer side where they bear against the cylinder walls when the ring is mounted on the piston- The depth or radial thickness of the tongues to is three-fifths or the depth of the ring at the oint, and the shoulders are two-fifths of the rmgs depth. By making the tongue radially thiclrer than its coiiperating shoulder, the liability of the tongue to break or as snapotf is obviated. V7 hen the tongues and shoulders are ot the same radial thickness the rorrner are weaker than the latter as they are merely reduced tips projecting beyond the body out thering. while the shoulfill ders are formed by merely undercutting the body and so have the support afforded along one entire side by the lateral metal of the body to strengthen them. W hen these parts are so made the inner tongues are apt to 55, break when the ring is compressed for insertion in the cylinder and also after it has been used; when the ring is compressed to insert it in the cylinder the strain on the tongue is sudden and great, and after the so ring is in place the pressure on the extended or prolonged tongue tends to snap it oil, this latter tendency increasing as the rings expand in use or in oversize cylinders by reason of the stress or strain moving away fromas the base of the tongue and increasing more ans-rare and more toward its end, while in both these relations the outer shoulder is confined and backed by the cylinder wall and so is additionally strengthened. By reducing the radial thickness of the shoulder its liability to brealr'is not increased owing to the fact that it is always strengthened by the lateral metal or the body and backed by the cylinder-wall, and by transferring a corresponding amount of metal to the inner tongue by" '7 increasing its radial thickness it is in turn strengthened and its liability to break off is obviated. The round notches are important as they give strength to the tongue by making it wider at its base, and help make the seal. The round end or tip of the tongue and shoulder is important when placing the rings in the cylinder so that they will not catch as they slip past each other, and they also help to make the seal. The curved 35 laces of the tongues and-shoulders make a surface seal with a circuinferentially elongated bearing, instead of an edge or ledge seal.

litter the joint is rnilled the sides of the ring are ground true to the desired width. The ring is then clamped in closed position and tie crust on tie periphery of the ring is removed by rough turning or grinding the ring to sligh ly larger than the finished lit size and the ring is then released from the clamp. After the ring is roughed slightly larger than the finished size. it is then open-ed as shown in Fig. 7 so that it will slip over the piston into the groove of which it is-to lit, and while in this position its ends are oppositely passed back and forth; one end, designated E, is moved to position 12 Figs. 8, and 9 and the other end E, is moved to position 8 simultaneously; and 1 then end l5) is moved to position 9, and end E to position 11 simultaneously. This treatment being carried out while the ring is expanded as shown at 7, sets the particles in the'ring the same as if the mug was sprung over a piston into the groove thereof. so that it is not deformed when finally so sprung into place.

The ring; is then finished by closing the joint and clamped into a suitable holder and 11 while in this position the periphery is ground to finished size, when the ring is removed from the clamp and is ready for use.

1 claim 2- 1. A one-piece paclringring having a no joint formed bytwo meeting ends. each end being cut-away to form an outer shoulder and an inner tongue on opposite sides of its median line, each tongue being of greater radial thickness than its overlying shoulder 12s and concentric therewith.

2. A packing ring having a joint comprising pairs of overlapping inner tongues and outer shoulders on the opposite sides of its median circumferential dividing line, 13o

each pair of said tongues and shoulders hav In testimony whereof I aifix my signamgil opposlng seats extended circumferenture in presence of two Witnesses.

tia y and providing prolonged seals on a T line concentric with the curvature of the EDWARD LORMAN' 5 ring, and each tongue being of greater ra- Witnesses:

dial thickness than its cooperatmg shoul- V J. MoRoBERTs,

der. EDITH H. Wrnoox. 

